package collection;

import java.util.ArrayList;
import java.util.Collection;
import java.util.HashSet;

/**
 * 演示contains()和remove()方法
 */
public class CollectionDemo2 {
    public static void main(String[] args) {
        //Collection c = new HashSet();
        Collection c = new ArrayList();
        c.add(new Point(1,2));
        c.add(new Point(3,4));
        c.add(new Point(5,6));
        c.add(new Point(7,8));
        c.add(new Point(9,0));
        boolean b = c.add(new Point(1,2));
        System.out.println(b); //对于HashSet集而言为false，因为是否重复取决于元素的equals()结果
                               //对于ArrayList集而言为true，因为ArrayList是可重复集
        //[元素1.toString(), 元素2.toString(), 元素3.toString(), ......]
        System.out.println(c); //[(1,2), (3,4), (5,6), (7,8), (9,0), (1,2)]

        /*
          boolean contains(object o):
          判断当前集合是否包含给定元素o，若包含则返回true，否则返回false
          判断依据是给定元素与当前集合元素是否存在equals()为true的情况
         */
        Point p = new Point(1,2);
        boolean contains = c.contains(p);
        System.out.println("是否包含:"+contains); //true

        /*
          boolean remove(Object o):----------一般都不接收boolean结果
          从当前集合中删除与给定元素o的equals()比较为true的元素，删除成功为true，否则为false
          若存在重复元素则只删除第1次匹配的元素
         */
        boolean remove = c.remove(p);
        System.out.println("是否删除:"+remove); //true
        System.out.println(c); //[(3,4), (5,6), (7,8), (9,0), (1,2)]

    }
}















